From 4ef3e45d7c6ec3c482a1a48f4df470811aa3cf0a Mon Sep 17 00:00:00 2001
From: buzbee <buzbee@google.com>
Date: Fri, 14 Dec 2012 13:35:28 -0800
Subject: Compiler constant handling rework

In preparation for de-optimization, reworked the constant
handling mechanism.  Also took advantage of knowledge of
constant operands (particularly for long operations).

Significant performance improvements for Mandelbrot
(~60 seconds to ~34 seconds).  Minor improvements in other
benchmarks.

The new constant handling breaks two of the existing
optimization passes: "Skip Large Method" and "Load/Store
Elimization."

I don't intend to update the large method optimization
because it will be superceeded by the upcoming interpreter/
fingerprinting mechanism.  Leaving the code in place for
now in order to compare compile-time improvements with
fingerprinting/interpret.  All related code will be deleted
when that is complete.

The load/store elimination pass needs some rework to handle
uses of multiple-register loads and stores.  It will be
updated & restored in a future CL.

Change-Id: Ia979abaf51b8ae81bbb0428031cbcea854625fac
---
 src/compiler/codegen/codegen_util.cc | 45 +++++++++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

(limited to 'src/compiler/codegen/codegen_util.cc')

diff --git a/src/compiler/codegen/codegen_util.cc b/src/compiler/codegen/codegen_util.cc
index ad05b93c8d..57d932f6e3 100644
--- a/src/compiler/codegen/codegen_util.cc
+++ b/src/compiler/codegen/codegen_util.cc
@@ -23,6 +23,27 @@
 
 namespace art {
 
+bool IsInexpensiveConstant(CompilationUnit* cu, RegLocation rl_src)
+{
+  bool res = false;
+  if (rl_src.is_const) {
+    if (rl_src.wide) {
+      if (rl_src.fp) {
+         res = cu->cg->InexpensiveConstantDouble(ConstantValueWide(cu, rl_src));
+      } else {
+         res = cu->cg->InexpensiveConstantLong(ConstantValueWide(cu, rl_src));
+      }
+    } else {
+      if (rl_src.fp) {
+         res = cu->cg->InexpensiveConstantFloat(ConstantValue(cu, rl_src));
+      } else {
+         res = cu->cg->InexpensiveConstantInt(ConstantValue(cu, rl_src));
+      }
+    }
+  }
+  return res;
+}
+
 void MarkSafepointPC(CompilationUnit* cu, LIR* inst)
 {
   inst->def_mask = ENCODE_ALL;
@@ -202,6 +223,9 @@ void DumpLIRInsn(CompilationUnit* cu, LIR* lir, unsigned char* base_addr)
       LOG(INFO) << "-------- entry offset: 0x" << std::hex << dest;
       break;
     case kPseudoDalvikByteCodeBoundary:
+      if (lir->operands[0] == 0) {
+         lir->operands[0] = reinterpret_cast<uintptr_t>("No instruction string");
+      }
       LOG(INFO) << "-------- dalvik offset: 0x" << std::hex
                 << lir->dalvik_offset << " @ " << reinterpret_cast<char*>(lir->operands[0]);
       break;
@@ -471,6 +495,8 @@ LIR* ScanLiteralPoolWide(LIR* data_target, int val_lo, int val_hi)
   LIR* lo_target = NULL;
   while (data_target) {
     if (lo_match && (data_target->operands[0] == val_hi)) {
+      // Record high word in case we need to expand this later.
+      lo_target->operands[1] = val_hi;
       return lo_target;
     }
     lo_match = false;
@@ -488,7 +514,7 @@ LIR* ScanLiteralPoolWide(LIR* data_target, int val_lo, int val_hi)
  * instruction streams.
  */
 
-/* Add a 32-bit constant either in the constant pool */
+/* Add a 32-bit constant to the constant pool */
 LIR* AddWordData(CompilationUnit* cu, LIR* *constant_list_p, int value)
 {
   /* Add the constant to the literal pool */
@@ -1097,4 +1123,21 @@ bool EvaluateBranch(Instruction::Code opcode, int32_t src1, int32_t src2)
   return is_taken;
 }
 
+// Convert relation of src1/src2 to src2/src1
+ConditionCode FlipComparisonOrder(ConditionCode before) {
+  ConditionCode res;
+  switch (before) {
+    case kCondEq: res = kCondEq; break;
+    case kCondNe: res = kCondNe; break;
+    case kCondLt: res = kCondGt; break;
+    case kCondGt: res = kCondLt; break;
+    case kCondLe: res = kCondGe; break;
+    case kCondGe: res = kCondLe; break;
+    default:
+      res = static_cast<ConditionCode>(0);
+      LOG(FATAL) << "Unexpected ccode " << before;
+  }
+  return res;
+}
+
 } // namespace art
-- 
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